John P. Holland, the inventor of the submarine boat which bears his name, is an Irishman by birth. He is now about sixty years of age, hale, hearty and devoted to the task of improving the wonderful craft of which he is the creator. Mr. Holland reached this country early in the 70’s, but long before that he had come to the conclusion that much of the naval warfare of the future would be done beneath the water rather than on its surface. He states that his convictions in this respect were the outcome of a newspaper account of the fight between the Monitor and Merrimac, which he read about two weeks after the occurrence of that historical conflict. From that time on, he began to form plans and make models for submarine torpedo boats or destroyers. He not only had to contend with great mechanical difficulties, but even when his boat was so far perfected that it could be submitted to the authorities, he encountered prejudices and opposition of the strongest. As the matter now stands, the most conservative of naval experts have become convinced of the importance of the Holland submarine, that, too, not only in this country but abroad. The United States now owns a number of the boats, as does Great Britain. Mr. Holland, when he first came to this country, was a school teacher, and, like the majority of inventors who are not capitalists, had a hard time of it for many years. He was at length fortunate enough to interest some moneyed men in his invention and was enabled to devote himself entirely to it. It is said that his creations provide for every contingency, both above and below water. It was only after prolonged tests of their efficiency that the U. S. government added them to the navy. WILLIAM MARCONI.